Federal Way, WA Accessory Structures: ADU Permits (2026)

How to apply for an ADU building permit: application steps, plan-check requirements, review timelines, ministerial vs discretionary review, and which department to file with.

Research in progress

We are currently verifying Federal Way's specific local ordinance for adu permits. In the meantime,Washington state law generally applies, and below you'll find guidance for finding the official rules and links to related Federal Way ordinances we've already verified.

Washington State Law Context

Washington state law provides the baseline framework for adu permits across all municipalities in the state. Individual cities like Federal Way may adopt additional local rules on top of state requirements, which is what makes checking your specific city ordinance important. For Federal Way residents, the safest approach is to follow state law as a baseline and contact City Hall for any additional local requirements.

You can browse all Washington accessory structures to see how cities across the state regulate this topic.

How to find official Federal Way ADU Permits rules

Search for "Federal Way WA municipal code" to find your city's online code portal (Municode, eCode360, or American Legal Publishing are the most common).
Look for chapters covering accessory structures, zoning, nuisance, or property maintenance — that's where most adu permits rules live.
Contact Federal Way City Hall's code enforcement, planning, or community development department for clarification.
Check with your HOA if applicable — many HOAs have stricter rules than the city itself.

Other accessory structures verified for Federal Way

We've verified the following accessory structures for Federal Way:

Federal Way Carport Rules Federal Way Tiny Home Rules Federal Way ADU Rules Under HB 1337 Federal Way Shed Rules and Permit Thresholds Federal Way Garage Conversion Rules

ADU Permits in nearby cities

See how nearby King County cities regulate adu permits:

Seattle Bellevue Kent

Frequently Asked Questions

Does Federal Way have a specific adu permits ordinance?

We are still researching Federal Way's specific local ordinance for adu permits. In most cases, Washington state law provides the baseline rules that apply throughout the state, and individual municipalities may add stricter local requirements on top.

Where can I find official adu permits rules for Federal Way?

The most authoritative source is the Federal Way municipal code, typically hosted on platforms like Municode, eCode360, or American Legal Publishing. You can also contact Federal Way City Hall or the relevant city department directly. We are working to surface the specific code sections on this page soon.

What happens if I violate adu permits rules in Washington?

Penalties vary by jurisdiction. Washington state law sets minimum standards, while individual cities may impose additional fines or enforcement procedures. Code enforcement violations are typically handled through warnings, citations with monetary fines, and in repeat or serious cases, court proceedings.

Are there other accessory structures I should know about in Federal Way?

Yes — accessory structures typically include several related rules. Check the related topics section on this page for Federal Way-specific information that we have already verified.

Washington State Law Context